Lockheed Martin's proposal was made in response to a call from Japan's Ministry of Defense, which is weighing options to boost Japan's defensive capabilities in the face of rising regional tensions.

Japan is looking to replace its aging fleet of around 90 F-2 fighters and is mulling three possibilities. The first would be for Japan to develop a new jet domestically. The second would be co-development with foreign defense contractors, such as Lockheed Martin. The third would be to buy more existing aircraft -- say, Lockheed Martin's F-35 stealth jet.

The Japanese ministry's deliberations are ongoing, with a second round of information requests to be made by the end of next March. "We will definitely respond [to this request], we will be a part of that process," Hewson said. A final decision is expected in fiscal 2018.

Lockheed Martin rival Boeing has also proposed working with MHI on a replacement for the F-2. Alternatively, the Japanese contractor could opt to go it alone with its experimental stealth fighter, which made its maiden flight in April.

Japan has already purchased 42 F-35s from Lockheed Martin to replace its F-4 fleet. The F-35 was originally developed by the U.S. and eight other countries, including the U.K. and Italy, in what has been described as the world's largest weapons program.